How to change COM port modem assignment

Posted on 2004-11-20
Last Modified: 2013-12-11
WinME machine had a perfectly functioning modem then I used MS Windows Update to load a new driver. Never worked since.  Lesson learnt.
The modem is an internal 'Motorola SM56 Voice Modem' according to ME, although ATI7 reports 'Motorola SM56 PCI Fax Modem' so I tried several of the confusingly similar modem drivers on Motorola's Web site until I found one which causes the device to show in Device Manager without errors.

I ran CheckIt and that finds it on COM3 and test dials out on it fine.  But I only have COM1 and COM2 available under Control Panel, Modem Properties; so trying to dial out on it gives an error 630.

How to cause it to switch COM ports please ?  I do not have the original setup CD. The hardware IRQ settings are currently:

 0 System timer
 1 Standard 101/102-Key or Microsoft Natural Keyboard
 2 Programmable interrupt controller
 3 Communications Port (COM2)
 4 Communications Port (COM1)
 5 ACPI IRQ Holder for PCI IRQ Steering
 5 D-Link DFE-530TX PCI Fast Ethernet Adapter (rev.C)
 5 VIA PCI Audio Controller (WDM)
 6 Standard Floppy Disk Controller
 7 Printer Port (LPT1)
 8 System CMOS/real time clock
 9 ACPI IRQ Holder for PCI IRQ Steering
 9 Motorola SM56 Fax Modem
 9 SCI IRQ used by ACPI bus
 10 ACPI IRQ Holder for PCI IRQ Steering
 10 VIA Tech 3038 PCI to USB Universal Host Controller
 10 VIA Tech 3038 PCI to USB Universal Host Controller
 11 ACPI IRQ Holder for PCI IRQ Steering
 12 PS/2 Compatible Mouse Port
 13 Numeric data processor
 14 Primary IDE controller (dual fifo)
 14 VIA Bus Master PCI IDE Controller
 15 Secondary IDE controller (dual fifo)
 15 VIA Bus Master PCI IDE Controller

Question by:EugeneGardner
    LVL 27

    Expert Comment

    You may find a lead here, even though the issue wasn't solved for the person named on the original message:
                >>   "How to change com port for modem"

    LVL 1

    Author Comment

    Thanks Jonvee - I had looked there.  Perhaps the questioner didn't get an answer due to his attitude.  This is what I have just done:

    I physically removed the modem; booted;
    deleted modem from ControlPanel, Modems; deleted COM1/2 from Device Manager;shutdown;
    set COM1 and COM2 to disabled in the BIOS (PNP set to No); booted;
    COM1 & COM2 reappeared in Device Manager!; shutdown;

    Physically inserted modem into PCI slot; (BIOS still has COM ports disbled); booted;
    In Control Panel, Modems, find PNP, none found, select fax modem from list
    Modem now appears as COM1 but fails to respond, changed to COM2, fails to respond;

    Run CheckIt, there it is on COM3 again :-(   Would a different driver help force it to use COM 1or 2 ?
    LVL 27

    Accepted Solution

    Another different driver would appear to be your next step although i'm not sure if this would definitely
    solve the COM 1 or 2 issue. Couple of links here may help, although you may have seen the first one:   

    You could take a look here at section 6, "Troubleshooting":
    LVL 27

    Assisted Solution

    It's been several days and you may well have resolved your COM 1 and 2 problem by now!  If not, and if you get no further suggestions, you might like to consider an 'over the top' Me reinstall.   You should not lose any of your files, even if you are unable to back them up.  However please note that WMP9 and IE6 would first have to be uninstalled, if you are running them (see 1st link below).  
    Should you prefer to reinstal using "Setup", then the 2nd link may be of more use:
    LVL 1

    Author Comment

    Thanks for the comments.  The problem is now resolved.  I found a new modem with original driver CD and was able to install that to COM3 after I put the BIOS settings back to their original (auto everything).
    LVL 27

    Expert Comment

    Glad you solved the problem.              
                                                     .. thank you.        Jonvee.          

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    What Security Threats Are You Missing?

    Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

    Today companies are subjected to more-and-more data, and it won't stop any time soon.  But there are obvious opportunities for reducing data, particularly data duplicated among companies.
    Join Greg Farro and Ethan Banks from Packet Pushers ( and Greg Ross from Paessler ( for a discussion about smart network …
    An overview on how to enroll an hourly employee into the employee database and how to give them access into the clock in terminal.
    With the advent of Windows 10, Microsoft is pushing a Get Windows 10 icon into the notification area (system tray) of qualifying computers. There are many reasons for wanting to remove this icon. This two-part Experts Exchange video Micro Tutorial s…

    779 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    13 Experts available now in Live!

    Get 1:1 Help Now